Medical assemblies and methods for implantation of multiple medical leads through a single entry

ABSTRACT

Assemblies and methods provide for implantation of multiple medical leads to a defined space within the body, such as the epidural space, through a single entry. A catheter having multiple lumens or alternatively a single oblong lumen may be used. A distal end of the catheter enters the defined space through the single entry such that the distal ends of the multiple lumens or the oblong lumen are present in the defined space. Medical leads are introduced through the multiple lumens or the oblong lumen into the defined space. In some cases, the distal end of the catheter may be deflectable to direct the medical leads within the defined space. In other cases, sheaths may be present within each lumen of the catheter where the sheaths may be extended into the defined space and deflect to direct the medical leads that are being passed through a lumen of the sheaths.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 61/498,906, filed Jun. 20, 2011, entitled “MedicalAssemblies and Methods for Implementation of Multiple Medical LeadsThrough a Single Entry”; and U.S.

Provisional Patent Application No. 61/498,914, filed Jun. 20, 2011,entitled “Medical Assemblies and Methods for Implementation of MultipleMedical Leads Through a Single Entry”, and both applications areincorporated by reference herein as if each is re-written in itsentirety.

TECHNICAL FIELD

Embodiments are related to medical assemblies for implantation ofmedical leads into a body. More particularly, embodiments are related tomedical assemblies for implantation of multiple medical leads through asingle entry to a defined space within the body.

BACKGROUND

Medical leads are implanted into a defined space within a body of apatient to provide medical therapy within the defined space. Forinstance, a distal end of one or more medical leads may be implantedwithin an epidural space of the patient in order to deliver electricalstimulation pulses from electrodes on the distal end of the lead(s). Theelectrical stimulation may be for various reasons, for instance, toprovide pain management.

In situations where multiple leads are needed, the conventional mannerof implantation is to perform two separate implantation procedures, witheach procedure creating a separate entry to the defined space. In theexample of the epidural space, each lead must pass through theligamentum flavum in order to enter the epidural space. The conventionalimplantation process involves puncturing the ligamentum flavum with aneedle large enough to pass a first medical lead through a lumen of theneedle. A needle is then used to again puncture the ligamentum flavum ata different site to allow a second medical lead to pass through theneedle and into the epidural space.

Each time an entry is created for each lead, there may be additionalpatient discomfort and inconvenience. Furthermore, there is also anincreased risk of complications such as an infection or other adversecondition. For instance, in the case of puncturing the ligamentum flavumto reach an epidural stimulation site, each puncture creates a risk ofalso puncturing the dura and causing a cerebral spinal fluid leak.

SUMMARY

Embodiments address issues such as these and others by providingassemblies that allow for implantation of multiple leads through asingle entry. In this manner, the risks and inconveniences of implantingmultiple leads may be reduced. For example, the assemblies may includefeatures such as catheters with multiple lumens, catheters with multiplesheaths, and/or catheters with a lumen having an oblong lateralcross-section. The leads may be implanted by being inserted through thelumens and/or sheaths of the catheters, where the catheter and/orsheaths may be deflectable so to facilitate directing the lead withinthe defined space of the body.

Embodiments provide a medical assembly that includes a catheter havingmultiple lumens and a deflectable distal end. A trocar is disposedwithin a first of the lumens, and a guide wire is disposed within asecond of the lumens.

Embodiments provide a medical assembly that includes a catheter havingmultiple lumens. A first sheath is disposed within a first of thelumens, the first sheath being deflectable. A second sheath is disposedwithin a second of the lumens, the second sheath being deflectable.

Embodiments provide a medical assembly that includes a catheter having alumen with an oblong lateral cross-section. A first sheath is disposedwithin the lumen, the first sheath being deflectable. A second sheath isdisposed within the lumens, the second sheath being deflectable.

Embodiments provide a medical assembly that includes a catheter having alumen with an oblong lateral cross-section and having a distal end witha pre-formed bend. An introducer is present within the lumen of thecatheter, and the introducer is positioned within the lumen at thedistal end of the catheter such that the pre-formed bend is heldstraight.

Embodiments provide a method of inserting a medical assembly. The methodinvolves inserting a needle into a defined space within a patient andfeeding a guide wire through a lumen of the needle to position the guidewire into the defined space. The method further involves removing theneedle while maintaining the guide wire within the defined space andfeeding a catheter with multiple lumens along the guide wire by passingthe guide wire through one of the multiple lumens. Additionally, themethod involves deflecting a distal end of the catheter when thecatheter enters the defined space.

Embodiments provide a method of inserting a medical assembly. The methodinvolves inserting a needle into a defined space within a body andfeeding a guide wire through a lumen of the needle to position the guidewire into the defined space. The method further involves removing theneedle while maintaining the guide wire within the defined space andfeeding a catheter with multiple lumens along the guide wire by passingthe guide wire through one of the multiple lumens. Additionally, themethod involves forcing a first sheath within one of the lumens of thecatheter into the defined space where the first sheath then deflects.

Embodiments provide a method of inserting a medical assembly. The methodinvolves providing a catheter with a lumen having an oblong lateralcross section, the catheter having an introducer present within thelumen, the introducer having a lumen, the catheter having a distal endwith a pre-formed bend that is straightened by the presence of theintroducer within the lumen of the catheter at the distal end. Themethod further involves feeding the catheter within the introducerpresent within the lumen of the catheter along a guide wire by passingthe guide wire through the lumen of the introducer until the distal endenters a predefined space within a body. The method further involvesremoving the introducer to allow the distal end of the catheter toachieve the pre-formed bend within the defined space and inserting afirst medical lead and a second medical lead through the lumen of thecatheter with a distal end of the first medical lead and the secondmedical lead entering the defined space.

Embodiments provide a medical assembly that includes a catheter havingmultiple lumens and a deflectable distal end and a trocar disposedwithin a first of the multiple lumens. The medical assembly furtherincludes a needle disposed within a second of the lumens with a distaltip of the needle being exposed from the second of the lumens.

Embodiments provide a method of inserting a medical assembly thatinvolves inserting a needle into a defined space within a patient, theneedle being present within one lumen of a catheter having multiplelumens with a distal tip of the needle being exposed from the one lumen.The method further involves upon the needle and catheter entering thedefined space, retracting the needle within the one lumen and deflectinga distal end of the catheter within the defined space.

Embodiments provide a medical assembly that includes a catheter havingmultiple lumens and a deflectable distal end. The medical assemblyfurther includes a first sheath disposed within a first of the multiplelumens and a needle disposed within a second of the lumens with a distaltip of the needle being exposed from the second of the lumens.

Embodiments provide a method of inserting a medical assembly thatinvolves inserting a needle and a catheter into a defined space within apatient, the needle being present within one lumen of the catheterhaving multiple lumens with a distal tip of the needle being exposedfrom the one lumen. The method further involves upon the needle andcatheter entering the defined space, removing the needle from the onelumen and forcing a first sheath within one of the lumens of thecatheter into the defined space where the first sheath then deflects.

Embodiments provide a medical assembly that includes a catheter having alumen with an oblong lateral cross-section and an introducer presentwithin the lumen of the catheter, the introducer having a lumen. Aneedle is present within the lumen of the introducer with a distal tipof the needle being exposed beyond a distal end of the introducer andthe catheter.

Embodiments provide a method of inserting a medical assembly thatinvolves providing a catheter with a lumen having an oblong lateralcross section, the catheter having an introducer present within thelumen, the introducer having a lumen with a needle present within thelumen of the introducer with a distal tip of the needle exposed beyond adistal end of the introducer and catheter. The method further involvesinserting the needle into a body until the distal end of the needle andthe catheter enters a predefined space within the body and removing theneedle and the introducer. The method further involves inserting a firstmedical lead and a second medical lead through the lumen of the catheterwith a distal end of the first medical lead and the second medical leadentering the defined space.

DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a first example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter with multiplelumens and a deflectable distal end.

FIG. 1B shows one example of a trocar that may be used with the assemblyof FIG. 1A.

FIG. 1C shows another example of a trocar that may be used with theassembly of FIG. 1A.

FIGS. 2A-2E show the assembly of FIG. 1A during an implantationprocedure.

FIG. 3 shows a set of acts that utilize the assembly of FIG. 1A toimplant multiple medical leads.

FIG. 4 shows a second example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter with multiplelumens, each lumen containing a deflectable sheath.

FIGS. 5A-5B show the assembly of FIG. 4 during an implantationprocedure.

FIG. 6 shows a set of acts that utilize the assembly of FIG. 4 toimplant multiple medical leads.

FIG. 7A shows a third example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having a lumenwith an oblong lateral cross-section.

FIG. 7B shows a fourth example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having a lumenwith an oblong lateral cross-section and having sheaths within thelumen.

FIGS. 8A-8B show the assembly of FIG. 7A during one implantationprocedure.

FIGS. 8CA-8CB show the assembly of FIG. 7 during another implantationprocedure.

FIGS. 8DA-8DB show a fifth assembly utilizing a lumen with an oblonglateral cross-section during an implantation procedure

FIG. 9A shows a set of acts that utilize the assembly of FIG. 7A toimplant multiple medical leads.

FIG. 9B shows a set of acts that utilize the assembly of FIG. 7B toimplant multiple medical leads.

FIG. 9C shows a set of acts that utilize an assembly including multiplepaddle medical leads.

FIG. 10 shows a sixth example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having acentral lumen housing a guidewire.

FIG. 11 shows a seventh example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having acentral lumen housing a guidewire and having sheaths in lead lumens.

FIG. 12 shows an eighth example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having a lumenhousing an implantation needle.

FIG. 13A shows a ninth example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having acentral extended lumen housing an implantation needle.

FIG. 13B shows a tenth example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having acentral non-extended lumen housing an implantation needle.

FIGS. 14A-14C show the assembly of FIG. 12 during an implantationprocedure.

FIG. 15 shows a set of acts that utilize the assembly of FIG. 12 toimplant multiple medical leads.

FIG. 16 shows an eleventh example of an assembly for implanting multiplemedical leads through a single entry by way of a catheter having acentral lumen housing an implantation needle while including sheaths inother lumens.

FIGS. 17A-17B show the assembly of FIG. 16 during an implantationprocedure.

FIG. 18 shows a set of acts that utilize the assembly of FIG. 16 toimplant multiple medical leads.

FIG. 19 shows an assembly like that of FIG. 7A during an alternativeimplantation procedure.

FIG. 20A shows a set of acts that utilize the assembly of FIG. 7A duringthe alternative implantation procedure for implanting multiple medicalleads.

FIG. 20B shows a set of acts that utilize the assembly of FIG. 7B duringthe alternative implantation procedure for implanting multiple medicalleads.

FIG. 20C shows a set of acts that utilize the assembly of FIG. 7A duringthe alternative implantation procedure for implanting multiple medicalleads where at least one is a paddle lead.

DETAILED DESCRIPTION

Embodiments provide assemblies for implanting multiple medical leadsthrough a single entry to a defined space within the body, such as theepidural space. The assemblies include a catheter that may have featuressuch as multiple lumens, an extended lumen adjacent other lumens,multiple sheaths within one or more of the multiple lumens, and/or alumen having an oblong lateral cross-section. The various embodimentsmay utilize one or more of implantation needles, guidewires, and thelike to introduce the catheter into the defined space through the singleentry.

FIG. 1A shows one example of a medical assembly for implanting multiplemedical leads into a defined space within a body. The assembly includesa multi-lumen catheter 102 that may be implanted into the defined spaceto provide a passageway for the multiple leads to then be inserted. Thecatheter 102 includes a first lumen body 104 and a second lumen body 106that are integrally formed and may be a unitary structure, each defininga respective lumen 108, 110. In this example, the lumen body 104 is usedas a guide that follows along a guidewire 112 passing through the lumen108 where the guidewire 112 has already been inserted into the definedspace.

In this particular example, the catheter 102 has a deflectable distalend shown in FIG. 1A. This allows the distal end to deflect uponentering the defined space so as to avoid damaging the tissuessurrounding the defined space and so as to properly direct the leadsonce they are inserted. The deflectability may be achieved by having thecatheter be constructed of flexible materials. For instance, thecatheter may be constructed of nylon or similar materials, may have aninternal liner also constructed of nylon, and may also include aninternal reinforcement such as a braid constructed of a metal such asstainless steel. Furthermore, the deflectable end may be constructed ofshape memory materials such as Nylon, Polyurethane, or any otherthermoplastics, thermoplastic elastomers, and the like. The desired bendof the distal end may be pre-formed through a heat forming process, andthen held straight by a trocar so that once the trocar is removed, thedistal end achieves the bent configuration.

However, there may be a need for the distal end to be relatively stiffin order to penetrate through tissue that is present in the pathway tothe defined space. For instance, the defined space may be the epiduralspace where access is achieved by piercing through the ligamentum flavumthat requires a relatively stiff catheter 102 even where a needle haspreviously been inserted, especially when the needle is of a smallerdiameter than the multi-lumen catheter 102. Yet, the epidural space isbordered by the spinal cord such that care must be exercised whenattempting to insert objects such as catheters and leads into theepidural space.

To avoid damaging contact with the spinal cord, the catheter 102 has thedeflectable distal end such that upon entering the epidural space, thecatheter tip deflects as discussed above to an orientation largelyparallel to the spinal cord such as by following the guidewire 112and/or by using shape memory. However, to pierce the ligamentum flavum,the catheter 102 must have a rigid distal tip. To achieve this initiallyrigid but later deflectable configuration, a trocar 114 made of a rigidmaterial such as a hard plastic or metal is present within the lumen 110which creates a rigid distal tip and which holds the catheter in astraight configuration during insertion. The trocar 114 may beretractable, such as where the trocar 114 is solid as shown in FIG. 1Bsuch that the trocar 114 is retracted proximally once the ligamentumflavum is pierced to allow the distal tip of the catheter 102 to thendeflect such as by transitioning to a pre-formed bend. Alternatively,such as where the catheter relies upon the guidewire to controldeflection rather than shape memory, the trocar 114′ as shown in FIG. 1Cmay include a flexible region 118 such as a coiled area that can deflectand thereby allow the catheter 102 to deflect with the trocar 114′ inplace.

To also assist in piercing the tissue such as the ligamentum flavum, thelumen body 106 of the catheter 102 may include a beveled distal end 107.Likewise, the trocar 114, 114′ may include a beveled distal end 116which may be oriented with the bevel in the same plane as the bevel ofthe lumen body 106 as shown in FIG. 1A.

FIGS. 2A-2E show a series of phases of the multi-lumen catheter 102being inserted and the implantable medical leads ultimately beinginserted into the defined space. These phases are illustrated anddiscussed with reference to implantation into the epidural space of abody. However, it will be appreciated that the assemblies and techniquesmay also be applicable to other defined spaces within a body. FIG. 3shows a series of acts taken to progress through the phases of FIGS.2A-2E. Additionally, while a hub is not shown on a proximal end of theneedle and catheter, it will be appreciated that a hub may be presentfor each device to allow insertion and removal of the various objects.

FIG. 2A shows a needle 214 being inserted into a body 202 by passingthrough the skin 204 and through the ligamentum flavum 208, adjacentvertebral bones 206 pursuant to the needle operation 302 of FIG. 3. Theneedle 214 enters the epidural space 210 but care is exercised to avoidcontact with the dura or any other layers about the spinal cord 212.FIG. 2B shows a guidewire 216 being inserted into the epidural space 210by feeding the guidewire 216 through a lumen within the needle 214pursuant to the guidewire operation 304 of FIG. 3. The needle 214 isthen removed while maintaining the guidewire in position within theepidural space pursuant to a needle operation 306.

FIG. 2C shows the catheter 102 then being inserted into the epiduralspace 210 by feeding the catheter 102 along the guidewire 216 with theguidewire 216 passing through the lumen 108 of the lumen body 104pursuant to a catheter operation 308. The trocar 114 is then removedfrom the catheter 102 in this example where the trocar 114 is solidpursuant to a removal operation 310 which allows the catheter 102 to beinserted farther such that the distal tip deflects as it follows thepath of the guidewire 216 and/or deflects by achieving a pre-formedbend. Where the trocar 114′ is present and includes a flexible portion118, the trocar 114′ may remain in place as the distal end begins todeflect and then is removed once the catheter 102 is inserted to anapproximate final position within the epidural space. In either case,once the catheter 102 is inserted to the approximate final position, theguidewire 216 is then removed pursuant to the removal operation 310.

FIG. 2D then shows first and second implantable medical leads 218, 220being inserted through each lumen of the catheter 102 so that themedical leads 218, 220 are then directed into the epidural space and ina direction largely parallel to the spinal cord 212 and pursuant to aninsertion operation 312. Once the medical leads 218, 220 have reached anapproximate final position within the epidural space 210, the catheter102 is then removed pursuant to a removal operation 314 to leave themedical leads 218, 220 in position within the epidural space 210 asshown in FIG. 2E.

FIG. 4 shows another example of a medical assembly for implantingmultiple medical leads into a defined space within a body. The assemblyincludes a multi-lumen catheter 402 that may be implanted into thedefined space to provide a passageway for the multiple leads to then beinserted. The catheter 402 includes a first lumen body 404 and a secondlumen body 406 that are integrally formed and may be a unitarystructure, each defining a respective lumen 408, 410. In this example,the lumen body 404 may also be used as a guide that follows along aguidewire passing through the lumen 108 where the guidewire has alreadybeen inserted into the defined space.

In this particular example, the catheter 402 has first and seconddeflectable sheaths 412, 416 that are present within the multiple lumens408, 410, respectively. This allows the distal end of the sheaths todeflect upon the catheter 402 entering the defined space so as to avoiddamaging the tissues surrounding the defined space and so as to properlydirect the leads once they are inserted through lumens 418, 420 withinthe sheaths 412, 416. The sheaths 412, 416 may be deflectable byconstructing them from a flexible material. For instance, the sheathsmay be constructed of various layers and materials such as nylon, mayhave an internal liner also constructed of various materials such ashigh density polyethylene and the like, and may also include an internalreinforcement such as a braid constructed of a metal such as stainlesssteel. The sheaths 412, 416 may also utilize shape memory to establishpre-formed bends on the distal ends where the preformed bends are heldstraight by the catheter 402 and are achieved upon the distal ends ofthe sheaths 412, 416 exiting the distal end of the catheter 402.

While the distal end of the catheter 402 may be deflectable or may berigid, there may still be a need for the distal end to be stiffened by atrocar in order to penetrate through tissue that is present in thepathway to the defined space. As with the prior embodiment, the trocar114 may be retractable, such as where the trocar 114 is solid as shownin FIG. 1B or may alternatively include a flexible region 118, such as acoiled region, that can deflect and thereby allow the catheter 102 todeflect with the trocar 114′ in place as shown in FIG. 1C.

To also assist in piercing the tissue such as the ligamentum flavum, thelumen body 406 of the catheter 402 includes a beveled distal end likethe previous embodiment. Likewise, the trocar 114, 114′ may include abeveled distal end 116 which may be oriented with the bevel in the sameplane as the bevel of the lumen body 406 as show in FIG. 4.

FIGS. 5A-5B show a series of phases of the multi-lumen catheter 402being inserted and the implantable medical leads ultimately beinginserted into the defined space. These phases are also illustrated anddiscussed with reference to implantation into the epidural space of abody. However, it will be appreciated that the assemblies and techniquesmay also be applicable to other defined spaces within a body. FIG. 6shows a series of acts taken to progress through the phases of FIGS.5A-5B.

Initially, the phases of FIGS. 2A and 2B are performed along with theacts in the operations 302-310 discussed above and pursuant to aninitial operation 602. The sheaths 418, 420 may already be presentwithin the catheter lumens 408, 410 when inserting the catheter 402where in that case the guidewire 216 passes through the sheath lumen 418while a trocar 114 may be present within the sheath lumen 420. Theguidewire 216 and trocar 114, if any, are then removed.

Then, as shown in FIG. 5A, the distal ends of the sheaths 412, 416 areextended distally from the catheter 402 pursuant to the sheath operation604, allowing the distal ends of the sheaths 412, 416 to deflect asneeded to obtain an orientation largely parallel to the spinal cord 212.Then, as shown in FIG. 5B, the implantable medical leads 218, 220 areinserted through the sheath lumens 418, 420 to enter into the epiduralspace 210 and are guided by the sheaths 412, 416 into the orientationthat is largely parallel to the spinal cord 212 pursuant to the leadoperation 606. The sheaths 412, 416 and catheter 402 may then beremoved, individually or as a whole, pursuant to the removal operation608, which then produces the phase shown in FIG. 2E.

FIG. 7A shows another example of a medical assembly for implantingmultiple medical leads into a defined space within a body. The assemblyincludes a catheter 702 having a single lumen body 704 but with alateral cross-section having an oblong shape such as an ellipse that iscapable of receiving multiple medical leads. A removable introducer 708having a conical distal end for ease of insertion is present within anoblong lumen 706 of the catheter 702 to provide stiffness. Theintroducer 708 also includes a lumen 710 that may be used to receive aguidewire or a needle during insertion of the catheter 702 into thedefined space within the body. The catheter 702 may have a shape memoryproviding a pre-formed bend on the distal end which is held straight bythe introducer 708 and is achieved upon removal of the introducer 708.

FIG. 7B shows an example of a medical assembly where a catheter 712 hasthe single lumen body 704 with a lateral cross-section having an oblongshape. In this assembly, sheaths 714 and 716 having sheath lumens 718and 720 are present within the oblong lumen 706 of the catheter 712. Aswith sheaths in the embodiment of FIG. 4, these sheaths may be used toultimately guide the medical leads into place. The sheaths may bedeflectable so as to orient in a direction parallel to the spinal cord212 such as by being constructed of a flexible material and/or by beingconstructed of a shape memory material to provide pre-formed bends. Suchpre-formed bends may be held straight by the catheter 712 and thenachieved upon the distal ends being extended from the catheter 712. Thiscatheter 712 may utilize an introducer 708 which is then removed once inthe defined space within the body to allow insertion of the sheaths 714,716.

FIG. 8A shows an assembly including catheter 702 being inserted into theepidural space 210 in accordance with guidewire operation 902 of FIG. 9Aby following a guidewire 216 that has already been inserted pursuant tothe initial operation 900. FIG. 8B shows the lumen body 704 of thecatheter 702 in position with the medical leads 218, 220 being insertedthrough the lumen 706 pursuant to insertion operation 906 once theguidewire 216 and introducer 708 have been removed pursuant to removaloperation 904. Once the leads 218, 220 are present in their approximatefinal location, the catheter 702 is then removed pursuant the removaloperation 908, with the medical leads 218, 220 then being in position asshown in FIG. 2E.

FIG. 8CA shows an assembly including catheter 712 after insertion intothe epidural space 210 and removal of the introducer 708 and guidewire216 in accordance with the initial operation 910 of FIG. 9B. Here, thefirst and second sheaths 714, 716 are also inserted through the lumen706 pursuant to the sheath operation 912 and to extend the distal endsof the sheaths 714, 716 beyond the distal end of the catheter 712. Thisallows the distal ends of the sheaths 714, 716 to deflect into anorientation generally parallel to the spinal cord 212. FIG. 8CB showsthe leads 218, 220 being inserted through the sheaths 714, 716 untilthey reach their approximate final position pursuant to the leadoperation 914. The catheter 712 and sheaths 714, 716 are then removedpursuant to the removal operation 916 with the medical leads 218, 220being in position as shown in FIG. 2E.

FIG. 8DA shows an assembly including catheter lumen body 704 afterinsertion into the epidural space 210 and removal of the introducer 708and guidewire 216 in accordance with the initial operation 918 of FIG.9C. Here, first and second paddle leads 802, 804 are being insertedthrough the lumen 706 pursuant to the insertion operations 920 and 922.For some embodiments, the width of the paddle 806, 808 may be of a sizethat is too large for two paddles 806, 808 to be laterally adjacentwithin the oblong lumen 706. In that case as well as some others, onepaddle 806 is inserted first, at insertion operation 920, ahead of theother paddle 808 and moved distally down the catheter lumen body 704.The other paddle 808 is then inserted pursuant to the insertionoperation 922 such that the latter paddle 808 is adjacent to only thelead body of the lead 802 where the lead body has a smaller width thanthe paddle 806. Both leads 802, 804 are fully inserted through thecatheter lumen body 704 as shown in FIG. 8DB until reaching theirapproximate final positions. The catheter 702 is then removed pursuantto the removal operation 924 with the paddle leads 802, 804 being in anapproximate final position similar to that shown for percutaneous leadsin FIG. 2E.

FIG. 10 shows another embodiment of a medical assembly including acatheter 1000. This catheter 1000 includes multiple lumen bodies 1002,1004 that are integrally formed and may be a unitary structure, eachhaving a lumen 1008. In this particular embodiment, each of the lumenbodies 1002, 1004 has a beveled distal end 1006. Additionally, thisembodiment includes a dedicated guidewire lumen body 1010 that isintegral with the other lumen bodies and that extends distally beyondthe lumen bodies 1002, 1004 and includes a guidewire lumen 1012. Theguidewire lumen body 1010 may be made of a flexible material to allowthe guidewire lumen body 1010 to deflect as it follows the path of theguidewire 112 upon entering the defined space within the body. A trocarmay be positioned in each lumen body 1002, 1004 and may be retractedonce the distal end of the lumen bodies 1002, 1004 enter the definedspace.

The assembly of FIG. 10 is inserted into the epidural space in the samemanner as discussed above for the embodiment of FIG. 1A, utilizing thesame approach as illustrated in FIGS. 2A-2E and FIG. 3 except that thededicated guidewire lumen 1012 receives the guidewire 216 as shown inFIGS. 2B and 2C rather than the guidewire 216 being present within alumen of the lumen bodies that is used to introduce a medical lead.

FIG. 11 shows another embodiment of a medical assembly including acatheter 1100. Similar to the catheter 1000 of FIG. 10, this catheter1100 includes multiple lumen bodies 1102, 1104 that are integrallyformed and may be a unitary structure and define lumens 1106. Thiscatheter 1100 also includes a dedicated and deflectable guidewire lumenbody 1112 that receives the guidewire 112. However, this assembly alsoincludes sheaths 1114 and 1116 present within the lumens 1106 of thelumen bodies 1102, 1104. The distal ends of these sheaths 1114, 1116 maybe deflectable and/or have shape memory as discussed above for thesheaths present in other embodiments.

The assembly of FIG. 11 is inserted into the epidural space in the samemanner as discussed above for the embodiment of FIG. 4, utilizing thesame approach as illustrated in FIGS. 2A-2C, 5A-5B and FIG. 6 exceptthat the dedicated guidewire lumen 1112 receives the guidewire 216 asshown in FIGS. 2B and 2C rather than the guidewire 216 being presentwithin a lumen of the lumen bodies that is used to introduce a medicallead.

FIG. 12 shows an embodiment of a medical assembly that eliminates theuse of a guidewire during insertion. The assembly includes a catheter1200 that has multiple lumen bodies 1202, 1204 that are integrallyformed and may be a unitary structure with each having a lumen 1210,1212. Each of the lumens 1210, 1212 defined by the lumen bodies 1202,1204 may be substantially the same diameter. The distal end 1208 of thelumen body 1204 includes a beveled surface 1206 like that of theembodiment of FIG. 1A. However, an insertion needle 1214 is presentwithin the lumen 1212 of the lumen body 1202. In this example, theinsertion needle 1214 includes a beveled distal end 1216 having a lumen1218 that may include a removable trocar for added stiffness and to fillthe lumen 1218 during insertion. Further, a trocar may also be presentwithin the lumen 1210 to provide additional stiffness during insertion.

Upon the distal end of the catheter 1200 entering the defined spacewithin the body, the needle 1214 and any trocar within the needle 1214may be retracted as may any trocar present within the lumen 1210. Atthis point, the distal end of the catheter 1200 may be deflected, suchas by further movement and/or shape memory providing a pre-formed bend.

FIG. 13A shows another embodiment of a medical assembly that eliminatesthe use of a guidewire during insertion. The assembly includes acatheter 1300 that has multiple lumen bodies 1302, 1304 that areintegrally formed and may be a unitary structure with lumens 1310 andbeveled surfaces 1306 on the distal ends 1308 of each. The catheter 1300also includes a dedicated and deflectable needle lumen body 1312 thatreceives the insertion needle 1314. The insertion needle 1314 of thisexample includes a beveled tip 1316 and may also include a lumen 1318which may be filled by a trocar during insertion. In this particularexample, the dedicated needle lumen body 1312 defines a lumen having asmaller diameter than the lumen defined by the lumen bodies 1302, 1304that receive the medical leads.

The needle lumen body 1312 of this example extends distally beyond thedistal end of the lumen bodies 1302, 1304 that receive the medical leadsand may be flexible to deflect and/or may include shape memory so as toachieve a pre-formed bend upon removal of the insertion needle 1314. Themultiple lumen bodies 1302, 1304 may also be deflectable and/or includeshape memory so as to achieve a pre-formed bend upon removal of trocarspresent within the lumens 1310 during insertion into the defined space.

FIG. 13B shows another embodiment of a medical assembly like that ofFIG. 10 or 13A except that a dedicated lumen body 1332 of a catheter1320 terminates at or near the distal end of multiple lumen bodies 1322,1324 rather than extending farther distally. The dedicated lumen body1332 may be for purposes of receiving a guidewire where the catheter1320 is inserted in the same manner as the catheter 1000 of FIG. 10 ormay be for purposes of receiving an insertion needle where the catheter1320 is inserted in the same manner as the catheter 1300 of FIG. 13A. Ineither case, the distal end of the catheter may be flexible so as to bedeflectable and/or may include shape memory to establish a pre-formedbend. In this example, the dedicated lumen body 1332 defines a lumen1334 that has a smaller diameter than the lumen of the other lumenbodies.

FIGS. 14A-14C show a series of phases of the multi-lumen catheterembodiments of FIGS. 12-13B being inserted without the use of aguidewire and also show the implantable medical leads ultimately beinginserted into the defined space. While the catheter 1200 of FIG. 12 isspecifically illustrated, it will be appreciated that the same phasesand operations are also applicable to the catheters 1300 and 1320.

As with the discussion above in the various figures showing phases ofinsertion, these phases are illustrated and discussed with reference toimplantation into the epidural space of a body. However, it will beappreciated that the assemblies and techniques may also be applicable toother defined spaces within a body. FIG. 15 shows a series of acts takento progress through the phases of FIGS. 14A-14C. Additionally, while ahub is not shown on a proximal end of the needle and cathetercombination, it will be appreciated that a hub may be present to allowinsertion and removal of the various objects.

FIG. 14A shows the assembly including the catheter 1200 and theinsertion needle 1214 being inserted into a body 202 by passing theassembly including the catheter 1200 and insertion needle 1214 throughthe skin 204 and through the ligamentum flavum 208, adjacent vertebralbones 206 pursuant to the needle operation 1502 of FIG. 15. The needle1214 enters the epidural space 210 but care is exercised to avoidcontact with the dura or any other layers about the spinal cord 212. Theneedle 1214 and any trocars may then removed from the needle 1214 andcatheter 1200 pursuant to removal operation 1504 to allow the distal endof the catheter to deflect and/or if applicable achieve a pre-formedbend. The catheter 1200 is inserted further as the deflection occurspursuant to insertion operation 1506 to reach the position as shown inFIG. 14B.

FIG. 14C then shows first and second implantable medical leads 218, 220being inserted through each lumen of the catheter 1200 so that themedical leads 218, 220 are then directed into the epidural space and ina direction largely parallel to the spinal cord 212 and pursuant to aninsertion operation 1508. Once the medical leads 218, 220 have reachedan approximate final position within the epidural space 210, thecatheter 1200 is then removed pursuant to a removal operation 1510 toleave the medical leads 218, 220 in position within the epidural space210 as shown in FIG. 2E.

FIG. 16 shows another embodiment of a medical assembly including acatheter 1600 where a guidewire is not used for insertion. This assemblyis similar to that of FIG. 13A except that sheaths 1614 and 1616 arepresent within the lumens 1606 of lumen bodies 1602 and 1604 where theselumen bodies are integrally formed and may be a unitary structure. Thesesheaths 1614, 1616 may deflectable and or have a shape memory providinga pre-formed bend as discussed above for the sheaths of otherembodiments. The catheter 1600 includes a dedicated needle lumen body1610 and a needle tip 1608 extends from the needle lumen body 1610.Where the needle tip 1608 includes a lumen, a trocar 1618 may be presentto fill the lumen during insertion. In this example, the dedicatedneedle lumen body 1610 defines a lumen that has a smaller diameter thanthe lumen of the other lumen bodies.

It will be appreciated that variations to the catheter 1600 areappropriate for other embodiments that also utilize a needle in a lumento avoid using a guidewire. For instance, the assembly of FIG. 12 mayinclude sheaths like those of FIG. 16 during the insertion process oncethe needle 1214 and any trocars are removed. Similarly, sheaths may beused within the assemblies of FIGS. 13A and 13B.

FIGS. 17A-17B show a series of phases of the multi-lumen catheterembodiment of FIG. 16 being inserted without the use of a guidewire andalso show the implantable medical leads ultimately being inserted intothe defined space. While the catheter 1600 of FIG. 16 is specificallyillustrated, it will be appreciated that the same phases and operationsare also applicable to the catheters 1200, 1300, and 1320 where thoseassemblies utilize sheaths during the lead implantation process.

FIG. 17A shows a phase that occurs after the catheter 1600 has beeninserted into the defined space and the insertion needle and any trocarshave been removed from the catheter 1600 pursuant to initial operation1802 of FIG. 18. Additionally, the needle lumen 1610 has deflected, andthe first and second sheaths 1614, 1616 have been inserted and extendedthrough the catheter 1600 until the distal ends of the sheaths 1614,1616 exit from the catheter and deflect pursuant to the sheath operation1804. As shown in FIG. 17B, the first and second leads 218, 220 are theninserted through the sheaths 1614, 1616 until entering the epiduralspace and reaching an approximate final position pursuant to insertionoperation 1806. The catheter 1600 and sheaths 1614, 1616 are thenremoved pursuant to the removal operation 1808 while the leads 218, 220remain in their approximate final position such as that shown in FIG.2E.

FIG. 19 shows a medical assembly including a catheter 1900 beinginserted into the epidural space 210. This assembly is the same as thatof FIG. 7A except that an insertion needle 1902 is present within thelumen of the introducer that is present within the lumen of the catheter1900 such that a guidewire is not used during insertion. The catheter1900 is inserted into the epidural space pursuant to the initialoperation 2000 of FIG. 20A which includes inserting the catheter 1900,then removing the insertion needle. Additionally, the introducer is alsoremoved at the removal operation 2002 which may occur in unison withremoval of the needle.

In one embodiment, the catheter 1900 is inserted further as needed as ininsertion operation 2004, such as shown in FIG. 8B, until the distal endof the catheter 1900 has deflected or established a pre-formed bendwithin the epidural space. The first and second leads 218, 220 are theninserted through the catheter 1900 until reaching an approximate finalposition within the epidural space 210 pursuant to the insertionoperation 2006. The catheter 1900 is then removed in a removal operation2008 with the leads being in the approximate final position as shown inFIG. 2E.

In another embodiment such as where the catheter 1900 utilizes sheathssimilar to that shown in FIG. 7B, once the catheter 1900 has beeninserted with an insertion needle in the lumen of the introducer withinthe catheter 1900, then the needle and introducer are removed pursuantto the initial operation 2010 of FIG. 20B. Then, first and secondsheaths are inserted through the oblong lumen in a sheath operation 2012until the distal end of the sheaths enter the epidural space and thendeflect into an appropriate position as shown in FIG. 8CA. First andsecond medical leads are then inserted through the sheaths untilreaching an approximate final position pursuant to insertion operation2014 and as shown in FIG. 8CB. The catheter 1900 and sheaths are thenremoved in a removal operation 2016 with the leads being in theapproximate final position as shown in FIG. 2E.

In another embodiment such as where the catheter 1900 is used to implantat least one paddle lead, once the catheter 1900 has been inserted withan insertion needle in the lumen of the introducer, then the needle andintroducer are removed pursuant to the initial operation 2018 of FIG.20C. For embodiments where the oblong lumen of the catheter canaccommodate one paddle and one lead body and where two paddle leads arebeing implanted, then the first paddle lead is inserted into the oblonglumen and moved distally in a paddle operation 2020 and as shown in FIG.8DA. Then, the second paddle lead is inserted trailing the first paddlein the oblong lumen so that the second paddle is laterally adjacent tothe lead body of the first paddle lead in a paddle operation 2022 and asshown in FIG. 8DB. Once the paddle leads have reached an approximatefinal position within the epidural space, then the catheter 1900 isremoved in a removal operation 2024 with the paddle leads being in theapproximate final position similar to that shown for percutaneous leadsin FIG. 2E.

While embodiments have been particularly shown and described, it will beunderstood by those skilled in the art that various other changes in theform and details may be made therein without departing from the spiritand scope of the invention.

What is claimed is:
 1. A medical assembly comprising: a catheter havinga lumen with an oblong lateral cross-section and having a distal endwith a pre-formed bend; and an introducer present within the lumen ofthe catheter, the introducer being positioned within the lumen at thedistal end of the catheter such that the pre-formed bend is heldstraight.
 2. The medical assembly of claim 1, wherein a guidewire ispresent within the lumen of the catheter.
 3. The medical assembly ofclaim 2, wherein the introducer comprises an introducer lumen andwherein the guidewire is also present within the introducer lumen whilebeing present within the lumen of the catheter.
 4. The medical assemblyof claim 1, wherein the introducer has an oblong lateral cross-section.5. The medical assembly of claim 1, wherein the catheter comprises ashape memory material.
 6. The medical assembly of claim 1, wherein theintroducer comprises a conical tip.
 7. The medical assembly of claim 6,wherein the conical tip extends beyond the lumen of the catheter.
 8. Themedical assembly of claim 1, wherein the pre-formed bend of the catheteris achieved once the introducer is removed from the lumen of thecatheter.
 9. A method comprising: inserting a needle into an epiduralspace; inserting a guidewire through the needle; removing the needlefrom the guidewire while the guidewire remains in the epidural space;providing an assembly comprising a catheter having a lumen and with anoblong lateral cross-section and a distal end with a pre-formed bend andthe assembly further comprising an introducer present within the lumento hold the pre-formed bend straight; inserting the assembly into theepidural space by guiding the assembly with the guidewire; removing theguidewire and the introducer; inserting at least one implantable medicallead through the lumen of the catheter and into the epidural space; andremoving the catheter from the epidural space.
 10. The method of claim9, wherein inserting the at least one implantable medical lead throughthe lumen of the catheter comprises inserting a paddle lead.
 11. Themethod of claim 9, wherein inserting the at least one implantablemedical lead through the lumen of the catheter comprises insertingmultiple paddle leads.
 12. The method of claim 11, wherein insertingmultiple paddle leads comprises inserting a first paddle lead ahead of asecond paddle lead.
 13. A medical assembly, comprising: a catheterhaving a lumen with an oblong lateral cross-section and having a distalend with a pre-formed bend; an introducer present within the lumen ofthe catheter, the introducer being positioned within the lumen at thedistal end of the catheter such that the pre-formed bend is heldstraight; and at least one implantable medical lead that is insertedinto the lumen of the catheter upon the introducer being removed fromthe lumen of the catheter.
 14. The medical assembly of claim 13, furthercomprising a guidewire present within the introducer.
 15. The medicalassembly of claim 13, wherein the at least one implantable medical leadcomprises a paddle lead.
 16. The medical assembly of claim 13, whereinthe at least one implantable medical lead comprises multiple paddleleads.
 17. The medical assembly of claim 16, wherein the multiple paddleleads are inserted into the lumen of the catheter with a first paddlelead ahead of a second paddle lead.
 18. The medical assembly of claim13, wherein the introducer has an oblong lateral cross-section.
 19. Themedical assembly of claim 13, wherein the catheter comprises a shapememory material.
 20. The medical assembly of claim 13, wherein theintroducer comprises a conical tip.